1. Field of Invention
The present invention relates generally to a tubular back beam for a vehicle and, more particularly, to a tubular back beam for a vehicle, which is manufactured in the form of a tube to satisfy crashworthiness.
2. Description of Related Art
As a measure to protect a passenger as well as a vehicle body against a crash, back beams are mounted to the front and rear of the vehicle.
FIG. 1 illustrates an example of a tubular back beam. A conventional tubular back beam 10 is configured so that upper and lower beams 11 and 12 each having a circular cross-section are spaced apart from each other in a vertical direction, and central portions of the upper and lower beams 11 and 12 are connected to each other using a connecting bracket 13. Stays 22 are provided on opposite ends of the upper and lower beams 11 and 12 to be coupled to side members 21.
The tubular back beam 10 configured as described above has a lower weight and less costs than a general integrated back beam. It is particularly advantageous because the upper and lower beams 11 and 12 can distribute and absorb the crash energy, respectively, thus more effectively satisfying crashworthiness.
However, the conventional tubular back beam 10 is problematic in that the upper and lower beams 11 and 12 are connected to each other using only one connecting bracket 13, so that the rigidity of the connection between the upper and lower beams 11 and 12 is low, and thus the crash energy separates the upper and lower beams 11 and 12 from each other, in which case it is impossible to effectively cope with a crash, thus increasing damage to a vehicle body and injury to occupants of the vehicle.
Further, the conventional tubular back beam 10 is problematic in that the connecting bracket 13 connecting the upper and lower beams 11 and 12 copes with a head-on crash, but there is no structure connecting the upper and lower beams 11 and 12 in the event of an offset crash of 40% or more, so that the back beam does not effectively cope with the offset crash.
An exemplar of the prior art is Japanese Patent Laid-Open Publication No. 2003-396437.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.